Tubular connection refacing apparatus and methods

ABSTRACT

An apparatus and method of using an apparatus for refacing a tubular connection is provided. In one example, the apparatus has a mandrel connectable to a threaded portion of a tubular connection and two face plates bearing cutters for refacing surfaces of the tubular connection. In this example, the cutting is controlled by an engaging nut moving along a threaded portion of a drive shaft, and the two face plates may be spaced apart at a fixed distance to maintain the distance between the torque-stop surface and the primary surface after refacing. Also, the apparatus uses a locking pin to assist in tightening or loosening the mandrel into place using the remainder of the apparatus. An air-oil system is provided to supply air and oil to the cutting surfaces as the apparatus refaces the shoulders of the connection. An exemplary pin refacer and an exemplary box refacer are both disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of, and claims priority to,U.S. patent application Ser. No. 14/463,472, filed 19 Aug. 2014 andentitled “TUBULAR CONNECTION REFACING APPARATUS AND METHODS,” now U.S.Pat. No. 9,623,485 issued on 18 Apr. 2017, which claims the benefit ofpriority to provisional U.S. Patent Application Ser. No. 61/867,488,filed 19 Aug. 2013, and the disclosures of both of the above-enumeratedapplications are hereby incorporated in their entireties by thisreference.

BACKGROUND

The following relates generally to apparatus for refacing tubularconnections, including both double-shoulder and single-shoulderconnections, with great accuracy and precision. The tools and methodsdescribed herein are particularly useful in the field of refacing drillpipe.

Tubular members, such as those used in oilfield applications, are oftenjoined by threaded rotary shoulder connections. For example, rotaryshoulder connections are used in the oil field to join sections of drillpipe and other related assemblies together. In a rotary shoulderconnection, the shoulders, also referred to as faces and seals, arepressed together by the threads. The thread flanks jack against eachother and push the shoulders into each other. The shoulders providestrength and integrity to the connection and also work as seals to sealfluid pumped through the inside of the pipe. In a conventional rotaryshoulder connection, each piece of pipe to be connected has oneface/seal. If the condition of the face/seal is not smooth, it can leakand result in a connection failure. In addition, over-torque of theconnection can over-stress the threads and shoulder and cause aconnection failure.

High torque connections overcome many of the disadvantages associatedwith conventional rotary shoulder connections. High torque connectionsinvolve two seals, a primary seal and secondary seal. In a high torqueconnection, the primary seal makes contact at the same time as thesecondary seal. The secondary seal serves as a torque-stop whichprevents the connection from being over-torqued and thereby avoids manyof the disadvantages associated with conventional rotary shoulderconnections.

Due to the primary and secondary seal design in high torque connections,it is critical that the length of the primary seal to the secondary sealremains the same. In establishing connections, both faces must be smoothand perpendicular to the thread direction to ensure a proper seal. If,however, a face is flawed or damaged with scratches, nicks, or otherirregularities, it must be refaced prior to being used. During use ofthe pipe and assembly components, connections may be repeatedly made upand broken resulting in repeated face-to-face contact and wear. Theresulting wear may result in sealing faces that are scored, nicked, orscratched or that no longer present a planar surface at right angles tothe longitudinal axis of the pipe. When such conditions occur, theface-to-face contact may not form a proper pressure seal, therebyleading to connection failures. The connection must then be refacedprior to use.

Prior attempts to recondition the faces of pipe have employed methodsthat are costly or inconvenient and equipment that is expensive and/orunavailable in the field. For example, the faces may be re-tooled in amachine shop. However, re-tooling in a machine shop involves expensiveand inconvenient transportation costs to transport the damaged/flawedpipe to the shop. There is a need for tools and/or methods for refacinghigh torque connections in the field.

U.S. Pat. No. 5,433,130 to Smith et al. describes portable shoulderdressing apparatuses. The shoulder dressing apparatuses include amandrel, a mandrel securing means for securing the mandrel to thethreaded end portion of the tubular connection; a piston assembly, thepiston assembly being axially and rotatably movable relative to themandrel; at least one cutter carried by said piston assembly; biasingmeans for applying a biasing force to the piston assembly to move thepiston assembly axially relative the at least one shoulder and to urgethe cutter into contact with the at least one shoulder, the biasingmeans being disposed between the mandrel and the piston assembly; androtating means for rotating the piston assembly while the pistonassembly is moved axially whereby the cutter can remove material fromthe at least one shoulder. In U.S. Pat. No. 5,433,130 the mandrel isattached to the connection via a threaded mandrel and the cutters arepressed into the shoulder to be refaced by a compression chamberemploying pneumatic or hydraulic pressure.

U.S. Pat. No. 5,852,962 to Camille Fraering describes a field tool toreface high-torque pipe connections. The tool is known in the field as“The Lightning Refacer.” The Lightning Refacer incorporates, inter alia,a spring-loaded cone that slides over the pin or box connection threads.The tool is held into position by the spring-loaded cone, then arotating body mounted with tungsten carbide cutters and powered by aportable driver, such as an 8″ angle grinder or Hole Hawg®, spins aroundthe cone to reface the target surface.

The Lighting Refacer, however, has shortcomings when used in the field.For example, the tool operator must apply equal pressure, keeping facesat a right angle to the threads while pushing the refacing tool towardsthe connection faces. If unequal pressure is applied, the primary andsecondary faces will be crooked with respect to the axis of the threads,and the length from one measurement to another measurement at 180degrees away from the first will not be within acceptable tolerances.Maintaining equal pressure can be difficult for an operator resulting incrooked faces that are not within acceptable tolerances. In addition,even if equal pressure is applied, the refaced faces may still becrooked with respect to the axis of the threads if the tool is operatedout of line with the axis of the threads. In addition, the tungstencarbide cutters can chip, causing irregularities on the face.Frequently, in high-torque connections used in drilling, the threadssharpen during repeatedly making up and breaking out the connection,resulting in threads that are raised and narrow. These sharpened threadsimpede the Lightning Refacer from easily sliding onto the threads.Furthermore, this the Lightning Refacer implements multiple mandrelelements, not only increasing the complexity and cost of the apparatus,but also decreasing the accuracy of the length dimension between theprimary and torque-stop faces of the threaded connection.

U.S. Pat. Application No. 2012/0132044 to Manwaring describes ahigh-torque refacing tool using a mandrel with bearings and two faceplates driven by a shaft-rotating driver, but has shortcomings incleaning debris and shavings from the surfaces being refaced, and relieson a user to provide equal pressure across the entire surface beingrefaced.

SUMMARY

According to at least one embodiment, an apparatus for refacing tubularconnections is described. Specific embodiments of the invention mayallow for refacing of either the male end (pin) or the female end (box)of the tubular connection. The apparatus may include at least a mandrelhaving a first end and a second end and a drive system extending acrossthe first and second ends of the mandrel. The drive system may berotatable independent of the mandrel and may include an engagementportion, a distal faceplate, and a proximal faceplate. These faceplatesmay have one or more cutters. The apparatus may also include an engagingnut that is movably connected to the engagement portion of thedriveshaft. The engaging nut may be linked to the distal and proximalfaceplates and provide longitudinal movement of the cutters uponlongitudinal movement of the engaging nut along the engagement portionof the driveshaft. The cutters can be adjusted longitudinally relativeto the mandrel in order to bring the cutters closer to or farther fromthe pipe surface(s) to be refaced.

In some embodiments, the apparatus further comprises a lubricant-airsystem providing lubricant-laden air to the cutters. The apparatus mayhave the engagement portion as a threading on which the engaging nut isthreaded. In some embodiments, the apparatus further comprises a driveunit that is operable to provide a torque to the drive system.

In another embodiment, an apparatus for refacing tubular connections isprovided. The apparatus may include a mandrel and a driveshaft extendingthrough the mandrel. The driveshaft may have a threaded portion and canrotate independent of the mandrel. A distal faceplate may be driven bythe drive shaft, and the distal faceplate may have one or more cutters.A proximal faceplate may also be driven by the driveshaft and may haveone or more cutters. On the threaded portion of the driveshaft, anengaging nut may be threaded that is linked to the distal and proximalfaceplates. The engaging nut may provide longitudinal movement of thecutters of the faceplates as it moves longitudinally along the threadedportion of the driveshaft.

Another apparatus for refacing tubular connections is also described. Itmay have a cutter linkage positioned around a mandrel, which cutterlinkage may include a distal faceplate and a proximal faceplate. Thefaceplates may have a plurality of cutters. A drive shaft may also beincluded which can provide a torque to the cutter linkage, therebyrotating the cutters. This driveshaft may have a threaded portionbearing an engaging nut. When the engaging nut advances on the threadedportion, the plurality of cutters of the cutter linkage may be advanced.

In another aspect, an apparatus for refacing tubular connections isprovided that may comprise a mandrel having a first end and a secondend. A drive system may extend across the first and second ends of themandrel, wherein the drive system may be rotatable independent of themandrel, and the drive system may include an engagement portion, adistal faceplate, and a proximal faceplate. The distal and proximalfaceplates may be adapted to connect to a plurality of cutters. Theapparatus may also comprise an engaging nut movably connected to theengagement portion of the drive system, wherein the engaging nut may belinked to the distal and proximal faceplates and provide longitudinalmovement of the plurality of cutters upon longitudinal movement of theengaging nut along the engagement portion of the drive system.

Additionally, the engagement portion may be threaded to the engagingnut. The apparatus may also have a drive unit operable to provide atorque to the drive system. The plurality of cutters may be configuredto engage at least two faces of a tubular connection simultaneously. Theplurality of cutters may comprise at least a bevel cutter and a facecutter.

The mandrel may comprise a central opening configured to receive atubular connection. In another embodiment, the mandrel may be configuredto extend into an interior of a tubular connection. The mandrel maycomprise threads that may be configured to threadably engage a tubularconnection. The mandrel may also be rotationally lockable to the distalfaceplate. For example, the mandrel may be rotationally lockable by apin extending through the distal faceplate.

The proximal and distal faceplates may be linked around their outerperimeters, and/or may be are linked by a shaft centrally connected tothe proximal and distal faceplates. The apparatus may also comprise abearing positioned between the mandrel and the drive system.

In another embodiment, a method of refacing a tubular connection may beprovided, with the method comprising at least attaching a mandrel to anend of a tubular connection and the tubular connection having at leastone face. The mandrel may be connected to a cutter apparatus, with thecutter apparatus having a drive system and at least one faceplateconfigured to be driven by the drive system. The at least one faceplatemay have at least one cutter. The method may further comprise rotatingthe at least one faceplate relative to the tubular connection using thedrive system without simultaneously rotating the mandrel and advancingthe at least one cutter into contact with the at least one face of thetubular connection, followed by removing material from the at least oneface with the at least one cutter.

In some embodiments, attaching the mandrel to the end of the tubularconnection may comprise synchronously rotating the mandrel and thecutter apparatus. The mandrel may also be threaded onto the end of thetubular connection.

In one of these methods, the at least one face of the tubular connectionmay include multiple faces, such as at least a proximal face and adistal face, and the at least one faceplate may comprise at least aproximal faceplate and a distal faceplate. In these embodiments,advancing the proximal and distal faceplates may include advancing theproximal faceplate toward the proximal face and advancing the distalfaceplate toward the distal face. The proximal and distal faceplates maybe advanced simultaneously.

In one method, the drive system may comprise a drive shaft threadablyengaged to a drive nut, wherein the at least one cutter is advanced byrotating a drive nut relative to the drive shaft.

In another aspect of the disclosure, an apparatus for refacing a tubularconnection is described, wherein the apparatus may include a mountingportion configured to mount to a tubular connection and a drive shaftrotatable independent of the mounting portion, wherein the drive shaftmay have a threaded portion. A drive nut may engage the threaded portionof the drive shaft, with the drive nut being linked to a cutterconfigured to remove material from the tubular connection uponadvancement of the cutter toward the tubular connection, and wherein thedrive nut may be configured to travel along the threaded portion of thedrive shaft upon the drive nut being held rotationally stationaryrelative to the drive shaft. In this apparatus, the mounting portion maymount to an inside surface or an outside surface of the tubularconnection.

The foregoing and other features, utilities and advantages of theinvention will be apparent from the following more particulardescription of a preferred embodiment of the invention as illustrated inthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings and figures illustrate a number of exemplaryembodiments and are part of the specification. Together with the presentdescription, these drawings demonstrate and explain various principlesof this disclosure. A further understanding of the nature and advantagesof the present invention may be realized by reference to the followingdrawings. In the appended figures, similar components or features mayhave the same reference label.

FIG. 1 is a perspective side view of an example pin refacer.

FIG. 2 is another perspective view of an example pin refacer.

FIG. 3 is another perspective view of an example pin refacer.

FIG. 4 is a perspective end view of a pin refacer with the refacerpartially disassembled while attached to a pin of a tubular connection.

FIG. 5 is a partial central cross-sectional, side-oriented view of a pinrefacer.

FIG. 6A is an end view of a primary face plate of a pin refacer.

FIG. 6B shows various cutter elements that may be used with a face plateof a refacer.

FIG. 7A is an end view of a torque-stop face plate of a pin refacer.

FIG. 7B shows example cutter elements that may be used with a face plateof a refacer.

FIG. 8 is an end view of a drive nut plate of a pin refacer.

FIG. 9 is an end view of a barrel of a pin refacer.

FIG. 10 is a perspective side view of a box refacer.

FIG. 11 is another perspective side view of a box refacer.

FIG. 12 is a perspective side view of a box refacer being used to refacea tubular connection.

FIG. 13 is a perspective end view of the distal end of a box refacer.

FIG. 14 is a side view of a box refacer engaging a box connection of atubular member.

FIG. 15 is a partial central cross-sectional, side-oriented view of abox refacer engaging a box connection of a tubular member.

FIG. 16 is an end view of a torque-stop face plate of a box refacerinstalled on a drive shaft.

FIG. 17A is a side view of a primary face plate of a box refacer.

FIG. 17B is an end view of a primary face plate of a box refacer.

FIG. 18 is a side view of a drive system of the box refacer.

FIG. 19 is a perspective top view of an air-oil attachment interface.

FIG. 20 is a flowchart showing an example embodiment method ofinstalling a refacing apparatus to a tubular connection.

FIG. 21 is a flowchart showing an example embodiment method of refacingusing a refacing apparatus installed at a tubular connection.

FIG. 22 is a flowchart showing an example embodiment method of removinga refacing apparatus installed at a tubular connection.

While the embodiments described herein are susceptible to variousmodifications and alternative forms, specific embodiments have beenshown by way of example in the drawings and will be described in detailherein. However, the exemplary embodiments described herein are notintended to be limited to the particular forms disclosed. Rather, theinstant disclosure covers all modifications, equivalents, andalternatives falling within the scope of the appended claims.

DETAILED DESCRIPTION

Apparatus, systems, and methods of refacing tubular connections aredescribed herein. The present description provides examples, and is notlimiting of the scope, applicability, or configuration set forth in theclaims. Thus, it will be understood that changes may be made in thefunction and arrangement of elements discussed without departing fromthe spirit and scope of the disclosure, and various embodiments mayomit, substitute, or add other procedures or components as appropriate.For instance, the methods described may be performed in an orderdifferent from that described, and various steps may be added, omitted,or combined. Also, features described with respect to certainembodiments may be combined in other embodiments.

Embodiments of the present disclosure may provide advantages including,for example, improved safety in operation of a refacing apparatus;individual, simultaneous, or sequential cutting of faces; portability ofa refacer which is movable to remote connection locations as needed; theability to reface surfaces with a tool operating at relatively lowspeeds (RPM); interchangeability of plates leading to adaptability todifferent types of tubular connections; and precise resurfacing throughprecise cutter control and/or through injection of oil and air ontocutters and a cutting surface to clean and lubricate while resurfacing.

A connection refacer may be described in some instances as a pin refaceror a box refacer. In some instances, the refacer may be referred to as atool. For example, a pin refacer may be a refacing apparatus configuredto at least partially receive a threaded pin of a tubular connection toreface at least one of the primary and secondary faces of the pin.Similarly, a box refacer may be a refacing apparatus configured to be atleast partially inserted into a threaded box of a tubular connection toreface at least one of the primary and secondary faces of the box. Forpurposes of this disclosure, a “pin connection” is a male connectionthreadably insertable into a female “box connection” of a tubularmember. For example, such a tubular member may be an oilfield pipe. Insome instances, the pin connection or box connection may be synonymouslyreferred to as a workpiece of a refacing apparatus.

A refacing apparatus may include a mandrel. A mandrel may be threadablysecurable to the threaded end of the tubular connection. A mandrel maybe provided with a mandrel securing means for securing the mandrel tothe threaded end portion of the tubular connection. A mandrel securingmeans may include a wrench or other leveraging device which may beremovable from the refacing apparatus. A pin mandrel may have a threadedinner surface for threadably engaging and fixably securing the pinmandrel to a threaded portion of a pin connection of a tubular member. Abox mandrel may have a threaded outer surface for threadably engagingand fixably securing the box mandrel to a threaded portion of a boxconnection of a tubular member. A mandrel may be composed of a metal, analloy, or a suitable composite or ceramic material. For example, themandrel may be made of steel, stainless steel, aluminum, titanium,copper, brass, metal alloy, plastic composite, polymer composite, orcarbon fiber composite. In addition, a mandrel may be covered with orconstructed of hard materials such as tungsten or chrome. When a mandrelis threaded to the tubular connection, thereby attaching the tool to thetubular connection, the mandrel may maintain a perpendicular orientationof the face plates of the refacing apparatus with respect to thelongitudinal axis of the connection or the direction of the threads ofthe connection. The mandrel may be advantageously removable andinterchangeable on the refacing apparatus, providing increasedflexibility to the types of tubular connections that a single refacingapparatus can provide.

A refacing apparatus may comprise a drive system. A drive system maytransfer a torque or rotationally-urging force to various portions ofthe apparatus, such as, for example, in driving the rotation of faceplates bearing cutters while against the shoulder faces of a workpiece.A drive system may include a shaft, which may be referred to as a driveshaft. A shaft may be composed of a metal, an alloy, or a compositesuitable for driving refacing plates. For example, the shaft may be madeof steel, stainless steel, aluminum, titanium, copper, brass, or metalalloy. The shaft may be cylindrical to accommodate its rotation with theaid of bearings, particularly in relation to the mandrel when themandrel is fixed in the threads of a workpiece, but may have sectionsthat are flattened or cubical to accommodate a wrench, lever, or anothertightening tool. A flattened portion may be referred to as a drive nut.In some embodiments, the drive nut may be a separate part that isremovably attachable to the drive shaft. In some embodiments, the drivesystem comprises a flattened portion for engagement with a drive unit. Adrive system may be driven manually using handles such as handlesconnected to the drive shaft or connected to face plates attached to thedrive shaft or which are otherwise locked in a stationary positionrelative to the drive shaft.

A drive unit may comprise a powered driving means. For example, thedrive unit may be an electric motor-driven torque wrench or other shaftdriving means. The drive unit may, for example, engage a portion of thedrive system such as a drive nut and thereby provide a rotational torqueto a drive shaft that is transferred to face plates and cutters.

The refacing apparatus may include one or more face plates. In someembodiments, two face plates are included. With two face plates, therefacing apparatus may advantageously reface multiple surfacessimultaneously, as described in further detail below. A face plate mayhave cutters positioned on a cutter mounting surface or cutter holder sothat the cutters may be provided to the faces of the tubular connectionduring operation. In some embodiments, the cutter mounting surface maybe a proximal or distal surface of the face plate. A face plateproviding a cutter to a torque-stop face of a tubular connection may bereferred to as a torque-stop face plate, and a face plate providing acutter to a primary face of a tubular connection may be referred to as aprimary face plate. A face plate may have a generally circular cuttermounting surface and a generally broad cylindrical shape. A torque-stopface plate may be sized to correspond with the diameter of thetorque-stop face of a tubular connection, and, as such, may have varyingdimensions to adapt to the target connection. Likewise, a primary faceplate may be sized to correspond with the diameter of the primary faceof the tubular connection and may vary in the diameter and size. A faceplate may be composed of a metal, an alloy, or a suitable composite. Forexample, the torque-stop or primary face plate may be made of steel,stainless steel, aluminum, titanium, copper, brass, or metal alloy.

In some embodiments, face plates are mounted to the drive system ordrive shaft. In a pin refacer, the threaded pin of the tubularconnection is inserted through the primary face plate, so it is notdirectly driven by or in contact with a drive shaft. Thus, a face platemay also be linked to another face plate, such as a primary face platein a pin refacer being linked around its perimeter to a torque-stop faceplate.

In some embodiments, the face plates are adjustable or interchangeable,providing adaptability to many different sizes and shapes of tubularconnections. For example, a face plate may be equipped with a bolt thatcan screw into a threaded hole in the drive shaft to attach the faceplate to the drive shaft. Thus, an appropriately-sized face plate may beinstalled as needed by the tubular connection encountered withoutrequiring a different refacing apparatus to perform a refacing. Aremovable or interchangeable face plate may facilitate easier cleaningand interchanging of cutting elements or abrasion surfaces. Thus, a faceplate may be attached to the drive system using fasteners such as screwsextending through a portion of the drive system and the face plate.Alternatively, the face plate may be welded or formed integrally withthe shaft or another portion of the drive system.

Some configurations include face plates bearing apertures or passagesfor bearing or transferring oil and/or air flow to a cutting elementpositioned distally on the face plate. For example, the face plate mayinclude an aperture for routing a tubing system from a proximal end of adrive system (e.g., exterior to the tubular connection) to a distal endof the face plate facing the refaced surface of the tubular connection.

In some embodiments, a peripherally linked system of face plates mayhave a barrel disposed between the face plates. A barrel may providesupport for a bearing between the inner or outer surface of the barreland a mandrel. A barrel may also be slidable along linkages that extendbetween the face plates so that the barrel (and bearing-held mandrelwith the barrel) is movable in relation to the face plates.

In another example, a face plate includes a feature adapted forconnection of a locking pin securing a face plate to the mandrel. Forexample, the feature may be an aperture through the face plate. Thelocking pin may be inserted through the aperture and then linked to themandrel. In some embodiments, the locking pin is inserted into a lockingrecess or hole in the proximal portion of the mandrel. This recess orhole may be threaded or otherwise configured for removably securing alocking pin to the mandrel. Advantageously, the locking pin may have anelongated portion for positioning in the mandrel and face plate and mayfurther comprise a handle portion extending normal from the elongatedportion. Such a handle portion may assist in inserting, removing, andloosening the locking pin to and from the face plate and/or mandrel. Onefunction of the locking pin may be locking the angular orientation ofthe face plate to the angular orientation of the mandrel, such as bylinking their rotation about the central axis of the drive shaft. Wheninstalling a mandrel to a tubular connection, the mandrel may beseparately rotatable from the drive system and other components of therefacing apparatus. This may lead to difficulty in properly insertingand tightening the mandrel onto or into the tubular connection,particularly when portions of the refacing apparatus cover the tubularconnection opening (e.g., in a box refacer) or restrict access to themandrel itself (e.g., in a pin refacer). A locking pin mayadvantageously lock the mandrel to the face plate or other portion ofthe drive system so that the mandrel may be properly tightened againstthe tubular connection by turning the drive system or face plate from amore accessible area of the apparatus. For example, with the locking pinin place, handles or wrenches may engage the face plate to therebypermit the user to rotate the entire apparatus in order to engage themandrel into the pipe threads. The locking pin is then removed beforeusing the tool to reface the surface(s) because, in use, the cuttersrotate relative to the mandrel as described herein.

Furthermore, one or more face plates of a refacing apparatus may have awrench or lever attachment means allowing a wrench or other lever to beconnected to the face plate and turn the face plate. For example, a faceplate may have an aperture or hole for receiving a portion of a leverthat extends radially outward from the face plate. Such attachment meansmay also comprise a bolt or stem configured to be engaged by a wrenchfor rotating the face plate around its central longitudinal axis. Insome embodiments, the face plate lockable to the mandrel includes alever connection aperture for receiving a tightening lever or wrenchthat allows the apparatus to be tightened to the tubular connectionusing leverage from an easily accessible exterior area of the apparatuswhile the mandrel is locked to the face plate.

In some embodiments, a face plate incorporates handles. Handles mayextend over or around the workpiece to assist in attachment or removalof the refacing apparatus from the workpiece while the locking pin is inan inserted position. In a pin refacer, the primary face plate may haveone or more handles extending distally from its distal surface. Multiplehandles may permit easier access to the handles while turning theapparatus. For example, the primary face plate may have four handlesoriented peripherally around its perimeter or circumference. A boxrefacer may incorporate handles as knobs or extensions directed outwardfrom a perimeter or circumferential surface of its primary face plate.For example, the primary face plate may have one or moreradially-extending knobs or bars. The handles may provide leverage whileattaching the mandrel to the tubular connection. In some configurations,the handles may be removably attached to a face plate, such as by a boltextending through the axis of the handle and into a face plate or anelement fixed to the faceplate.

In some embodiments, the face plates bear adjustable or repositionablecutters or other abrasive elements configured to be moved or reorientedfrom one portion of the face plate to another. In one exampleembodiment, the torque-stop face plate is configured to rotate andengage the torque-stop face of a box-end connection. A similarconnection may be made for the primary face of the connection. Thisengagement may remove material from the faces to provide for a properlength between the torque-stop face and the primary face and/or maysmooth the faces and remove irregularities, thereby providing for aproper seal in the tubular connection that is within acceptabletolerances.

A plurality of cutting elements, referred to herein generally ascutters, may be positioned on a distal surface of one or more faceplates. A face cutter or face cutting element may remove materialgenerally perpendicular to the longitudinal axis of the tubular member,and a bevel cutter or bevel cutting element may remove material at abeveled or angled direction from the axis of the tubular member. Forexample, a bevel cutter may remove material at a 45-degree angle fromthe central axis of the tubular connection. Advantageously, a refacingapparatus may be configured with two face plates, and in suchembodiments the face plates may bear two face cutters and two bevelcutters. This configuration may allow both the torque-stop surface andthe primary surface of a tubular member to be refaced (and beveled, ifneeded) simultaneously. Multiple cutters may be axially spaced on thesame face plate, with bevel cutters additionally positioned at differentaxial lengths from the axial lengths of face cutters. The number ofcutters employed may depend on the size of the connection to be refacedand the amount of material to be removed, since multiple cutters mayprovide faster removal of material. Cutters may be composed of toolsteel, tungsten carbide, ceramics, or other suitable materials forrefacing tubular members. In some examples, cutter tips may be attachedin wedges or a machine taper in a face plate. It will be understood thatcutters may also comprise abrasive elements, including withoutlimitation sandpapers, abrasive discs, diamond coatings, powder-coatedabrasives, or grit-based ceramics.

In some embodiments, cutters are removably attached to a face plate,providing easier servicing of parts and interchangeability andadaptability of the refacing apparatus to a variety of tubularconnections. Interchangeability may be provided by a bolt or nut, suchas a hex-nut inserted into a tapped hole. Additionally, removablyattachable cutters may be repositioned on the face plates or replaceablewith different cutters. In some embodiments, the cutters may be weldedor integrally formed with the face plate to provide added ruggedness andrigidity to the cutters and the face plate may be at least partiallyremovably interchangeable.

A refacing apparatus may also comprise an engaging nut. An engaging nutmay be positioned on the drive shaft such as on a threaded portion ofthe drive shaft. The engaging nut may be proximally located on thethreaded portion of the drive shaft proximal to the most proximal faceplate. An engaging nut may have a plurality of radially-extendinghandles to assist in advancing and retreating the engaging nut along thethreaded portion of the shaft. A distal portion of the engaging nut maycontact a drive nut plate.

A drive nut plate may be linked to a proximal face plate and rotate withthe proximal face plate when the shaft is driven. Therefore, when theengaging nut advances on the threaded portion of the drive shaft, suchas when it advances toward a distal end of the drive shaft, the drivenut plate transfers this advancement to the face plates. Alternatively,retreat of the engaging nut may cause the face plates to retreat in aproximal direction in relation to the drive shaft. In some embodiments,the drive nut plate may be attached to the engaging nut, providinglinkage of both advancement and retreat of the engaging nut to the faceplates. The connection between the engaging nut and the drive nut platemay comprise a fit such as an interference fit so that the engaging nutdoes not translate along the axis of the drive shaft relative to thedrive nut plate.

Advantageously, the engaging nut may be freely rotatable with respect tothe drive nut plate. In this example, when the drive shaft rotates, theengaging nut rotates at the same angular velocity as the shaft due tothe threaded connection between the shaft and an inside surface of theengaging nut. In this situation, when the engaging nut is heldstationary the drive engaging nut will advance or retreat (depending onthe direction of rotation of the shaft) along the threaded portion ofthe shaft due to the threading. Beneficially, the threaded portion ofthe shaft may be finely threaded to thereby provide slow and steadylongitudinal motion of the engaging nut. As the engaging nut translatesalong the threaded portion, the face plates follow the translation withrespect to the shaft via their link to the drive nut plate. Therefore,the engaging nut may provide fine-tuned control over the position of theface plates and ensure steady and even pressure of the face platecutters against the workpiece when refacing uneven surfaces and removingburrs, scratches, and other elements of the shoulders that are not tospecification.

In some embodiments, the refacing apparatus may include an oil-airsystem. An oil-air system may comprise an air supply (e.g., compressor),an oil reservoir, an oil-air routing system between the air supply andoil reservoir to the cutters. For example, a chuck may be positioned ata proximal end of the drive shaft linking a supply of compressed air andoil to a tube system through the drive shaft to a plurality of nozzlesfacing the cutting surfaces of the cutters on the refacing apparatus.The oil-air system advantageously may provide simultaneous cleaning andlubrication to the surfaces being refaced and the cutters. This may helpto ensure a clean working surface for the cutters and to assist inclearing away debris and shavings from the refaced surface while alsoproviding cooling and lubrication to preserve refaced shoulders andcutter surfaces. The oil-air system may also include an oil-airinterface providing a mixture of atomized oil with compressed air as itis provided to the refacing apparatus.

Turning now to the figures in detail, FIGS. 1-3 provide perspectiveviews of an example pin refacer 100. FIG. 1 is a perspective side viewof the pin refacer, FIG. 2 is a perspective end view of the distal endof the pin refacer, and FIG. 3 is a perspective end view of the proximalend of the pin refacer. As used herein, a proximal direction may bedefined as extending toward the end of the pin refacer 100 that extendsaway from the tubular connection when it is connected to the tubularconnection, and a distal direction may be defined as extending towardthe tubular connection when the pin refacer 100 is attached to thetubular connection. In some embodiments, the proximal direction may bedefined as extending into the tubular connection and the distaldirection may be defined as extending away from the end of the tubularconnection.

The pin refacer 100 may comprise a mandrel 102 (see FIG. 2). The pin ofthe tubular connection may be inserted into the mandrel 102 (see FIGS. 4and 5). A primary face plate 104 may be positioned in a distal directionor around the mandrel 102. The primary face plate 104 may include aproximal surface 106 and a distal surface 108. Primary face platehandles 110, cutter holders 112, an air-oil line 114 (see FIGS. 2 and 3)and line attachment tab 116 may extend from the distal surface 108. Theair-oil line 114 may be part of the air-oil system and may have an openend facing the cutter holders 112 for dispensing compressed air and oilto the area during cutting.

The primary face plate handles 110 may be attached to the ends of shaftguides 118 affixed through the primary face plate 104 and torque-stopface plate 120. The shaft guides 118 may set the distance between theface plates 104, 120. Shaft guides 118 may beneficially have dimensionsdetermined by the specifications of the tubular member being refaced inorder to provide cutters to the shoulders of the tubular member at thespecified dimensions of the shoulders. Additionally, cutters may beadjustably positionable to provide another level of adjustability andprecision to the apparatus. A barrel 122 or aluminum housing may bedisposed around the mandrel 102 and shaft guides 118. The barrel 122 mayhouse the mandrel 102 with bearings 402 (see FIG. 4) permitting themandrel 102 to rotate independent of the barrel 122. The torque-stopface plate 120 may bear cutter holders 124 extending from its distalface 126. A second air-oil line 128 may also be disposed passing throughthe torque-stop face plate 120 toward the cutter holders 124 to providecompressed air and oil to the cutting surfaces on the cutter holders124.

Drive nut plate pins 130 may pass through and primarily extendproximally from the torque-stop face plate 120 and may connect to thedrive nut plate 132. The distal ends of the drive nut plate pins 130 maybe connected to the barrel 122. An engaging nut 134 may extend throughthe drive nut plate 132. The engaging nut 134 may rotate in place withinthe drive nut plate 132. The engaging nut 134 may have removable handles136 screwed into threaded holes around the perimeter of the nut 134. Thehandles 136 may provide leverage for applying a torque to the engagingnut 134. Alternatively, the engaging nut 134 may have an outer surfaceconfigured to be turned by a wrench or other lever.

The engaging nut 134 may be in threaded connection with a threadedportion of a drive shaft 138. The drive nut plate 132 and pins 130 maykeep the engaging nut 134 and torque-stop face plate 120 aligned withthe drive shaft 138. The drive shaft 138 may extend through the engagingnut 134 and may connect to the torque-stop face plate 120. In someembodiments the drive shaft 138 may be welded to the torque-stop faceplate 120. In other embodiments, the drive shaft 138 may be removablyattached to the torque-stop face plate 120. The drive shaft 138 mayprovide rotational motion to the torque-stop face plate 120 and primaryface plate 104 via the shaft guides 118. Thus, the drive shaft 138, faceplates 104, 120, and shaft guides 118 may all be fixed in relation toeach other when assembled. Likewise, the barrel 122, drive nut platepins 130 and drive nut plate 132 may all be fixed in relation to eachother. The mandrel 102 may rotate within the barrel 122, but does nottranslate longitudinally. Similarly, the engaging nut 134 may rotatewithin the drive nut plate 132 but does not translate longitudinallywith respect to the plate. The movement of the engagement nut 134,however, may allow the positioning elements 122, 130, 132, 134 totranslate longitudinally in relation to the drive shaft-connectedelements 104, 118, 120, 138.

For example, when the drive shaft rotates 138, the drive shaft-connectedelements 104, 118, 120 and positioning elements 122, 130, 132, 134 mayalso rotate at the same rate. Note that the positioning elements 122,130, 132, 134 may rotate because of the pins 130 extending through thetorque-stop face plate 120. The engaging nut 134 will tend to rotate aswell, as it is driven by friction in the threaded drive shaft 138. Ifthe engaging nut 134 is stopped from rotating, however, such as by anoperator restraining one of the engaging nut handles 136, the engagingnut 134 may advance or retreat longitudinally along the drive shaft 138.This lateral movement may cause the drive shaft-connected elements 104,118, 120, 138 to move laterally as well. For instance, when the engagingnut 134 retreats proximally, the drive shaft-connected elements mayadvance distally in relation to the engaging nut 134, and vice versa. Inthis manner, the engaging nut 134 may cause the cutters to engage theshoulders of a tubular connection when the refacing apparatus isconnected to a tubular connection.

The drive shaft 138 may also include a drive nut 140, to which a driveunit may be attached. The drive nut 140 may be fixed to the drive shaft138 so the drive shaft 138 may be rotated by turning the drive nut 140.In some embodiments, the drive nut 140 may have multiple faces on whicha wrench or other drive system may be attachable. The drive shaft 138may also comprise a handle 142 rotatable independent from the rest ofthe drive shaft 138. The handle 142 may allow a technician to hold theproximal end of the apparatus 100 while operating the handles 110 on thedistal end so that when the mandrel 102 is loosened, the technician mayhave a stationary handhold for bearing the weight of the apparatus 100even while the remainder of the apparatus 100 spins due to turning theface plates and mandrel 102.

In some embodiments, a locking pin 144 may be employed which may beremovably inserted through the torque-stop face plate 120 and into themandrel 102 to synchronize their rotation. Thus, when a wrench or otherlever is attached to the torque-stop face plate 120 and applies atorque, the entire apparatus 100 will rotate together. This allows themandrel 102 to be tightened onto the tubular connection before refacingor to be loosened after refacing.

An air-oil chuck 146 may be disposed at the proximal end of the driveshaft 138 to provide a point of connection for a source of compressedair mixed with a lubricant, such as an oil, to supply the air-oil lines114, 128.

Referring now to FIG. 4, a perspective end view of a pin refacer isshown with the apparatus partially disassembled while attached to a pin400 of a tubular member. The bearing 402 can be seen between the pin 400and the barrel 122. The torque-stop face of the pin 400 has beenrefaced, including a refacing and a bevel of its outer edge. A pin 400in this case may be defined as a narrowed portion at the end of thetubular member that has a distal face that is the torque-stop face ofthe pin 400 and a proximal face that is the primary face of the pin 400.

FIG. 5 is a partial central cross-sectional, side-oriented view of a pinrefacer engaging a pin connection of a tubular member. The pin 400 maybe refaced in this embodiment by face and bevel primary shoulder cutters112 and a torque-stop face cutter 124 simultaneously. The bearing is notshown, but may be positioned between the barrel 122 and the mandrel 102.See bearing 402 in FIG. 4. The drive nut plate pins 130 are shown withlines indicating their connection to the barrel 122. Primary face platehandles (110 in FIG. 2), engaging nut handles (136 in FIG. 1), the drivenut (140 in FIG. 1), the air-oil system elements, and other features arenot shown in this view.

FIG. 6A shows an end view 600 of a primary face plate 104 of a pinrefacer having two cutter holders 112 and one cutter 602 installed.Various cutter elements 604 are shown in FIG. 6B, illustrating otherembodiments of cutters and cutter holders separated from the face plate104. Cutters and cutter holders may be configured for planar or beveledcutting, wherein a planar cutter may cut a face of a tubular connectionto be planar, and a bevel cutter may cut an edge of a tubular connectionto be beveled.

FIG. 7A shows an end view 700 of a torque-stop face plate 120 of a pinrefacer having two cutter holders 124 and two cutters installed. Othercutter elements 704 are also shown in FIG. 7B showing other embodimentsof cutters and cutter holders separated from a face plate 120.

FIG. 8 shows an end view 800 of a drive nut plate 132 of a pin refacer.An engaging nut 134 may be positioned within the central aperture 802,and peripherally-located drive nut pins (130 in FIG. 1) may bepositioned within the peripherally-located apertures 804. Theperipherally-located apertures 804 may be threaded to secure the drivenut pins 130.

FIG. 9 shows an end view 900 of a barrel 122 of a pin refacer. A bearing(402 in FIG. 4) and mandrel (102 in FIG. 5) may be positioned within thecentral aperture 902, shaft guides (118 in FIG. 1) may be positionedwithin the large peripheral apertures 904, and drive nut pins (130 inFIG. 1) may be positioned within or attached to the small peripheralapertures 906. The small peripheral apertures 906 may be threaded tosecure the drive nut pins (130 in FIG. 1). The sizes of the peripheralapertures 904, 906 are described here as relative to each other in viewof the embodiment shown, but in other embodiments their sizes may bechanged in relation to each other. For example, the small peripheralapertures 906 may be larger than the large peripheral apertures 904 insome embodiments.

FIGS. 10-13 provide perspective views of an example box refacer 1000.FIG. 10 is a perspective side view of the box refacer 1000; FIG. 11 is aclose-up perspective side view of the distal end of the box refacer1000; FIG. 12 is a perspective side view of the box refacer 1000refacing a tubular member; and FIG. 13 is a perspective end view of thedistal end of the box refacer. The box refacer 1000 may comprise amandrel 1002. A primary face plate 1004 may be positioned in a proximaldirection from the mandrel 1002. The primary face plate 1004 may includea distal surface 1008 and proximal surface (not shown; opposite thedistal surface 1008). Primary face plate handles 1010, cutter holders1012, and air-oil nozzle 1014 may extend from the distal surface 1008.The air-oil nozzles 1014 may be part of the air-oil system and may havean open end facing the cutter holders 1012 for dispensing compressed airand oil to the area during cutting.

The primary face plate 1004 may be attached to a drive shaft 1038. Atorque-stop face plate 1020 may also be attached to the drive shaft1038. The torque-stop face plate 1020 may have a cutter holder 1024 (seeFIG. 13) and an air-oil nozzle 1028 for providing compressed air and oilto the cutting surfaces on the cutter holder 1024. The cutter holder1024 and air-oil nozzle 1028 may extend radially from the torque-stopface plate 1020.

The attachment of the face plates 1004, 1020 to the drive shaft 1038 mayset the distance between the cutter holders 1012, 1024. A barrel 1022may be disposed within the mandrel 1002, with bearings (not shown)between the barrel 1022 and the mandrel 1002 allowing the mandrel 1002to rotate independent of the barrel 1022. A bearing seal 1300 (see FIG.13) and locking nut 1046 secure the bearings in place, tightly in oneembodiment with a minimum amount of slop in order to maintain tighttolerances of the cutters. In the embodiment shown in FIG. 13, a hole1050 is provided in the side of the mandrel 1002 to provide oil for thebearings disposed therein.

Drive nut plate pins 1030 may pass through the primary face plate 1004and connect to the drive nut plate 1032 (see FIG. 10). The distal endsof the drive nut plate pins 1030 may be connected to the barrel 1022. Anengaging nut 1034 may extend through the drive nut plate 1032. Theengaging nut 1034 may rotate in place within the drive nut plate 1032.The engaging nut 1034 may have removable handles 1036 screwed intothreaded holes around the perimeter of the engaging nut 1034. Thehandles 1036 may provide leverage for applying a torque to the engagingnut 1034.

The engaging nut 1034 may be in threaded connection with a threadedportion of a drive shaft 1038. The drive shaft 1038 may extend throughthe engaging nut 1034 and connect to the primary face plate 1004 andtorque-stop face plate 1020. In some embodiments the drive shaft 1038may be welded to the torque-stop face plate 1020 and the primary faceplate 1004. In other embodiments, the drive shaft 1038 may be removablyattached to the face plates 1004, 1020. For example, the torque-stopface plate 1020 may be secured to the end of the drive shaft 1038 by aface plate nut 1018. Additionally, the torque-stop face plate 1020 maybe further secured to the drive shaft 1038 by a longitudinal groove 1808(see FIG. 13) that receives a longitudinal tongue or bolt (not shown) ona drive shaft-facing portion of the face plate 1020. The drive shaft1038 may provide rotational motion to the torque-stop face plate 1020and primary face plate 1004. Thus, the drive shaft 1038 and face plates1004, 1020 may all be fixed in relation to each other when assembled.Likewise, the barrel 1022, drive nut plate pins 1030 and drive nut plate1032 may all be fixed in relation to each other. The mandrel 1002 mayrotate around the barrel 1022, but does not translate longitudinallyrelative to the barrel 1022. Similarly, the engaging nut 1034 may rotatewithin the drive nut plate 1032 without translating longitudinally withrespect to the plate. The movement of the engagement nut 1034, however,may allow the positioning elements 1022, 1030, 1032, 1034 tosimultaneously translate longitudinally in relation to the drive shaft1038 and the drive shaft-connected elements 1004, 1020. This causes thecutters to move longitudinally relative to the mandrel 1002 and thusmove closer to or farther from the work piece surface(s) to be refaced.

For example, once the tool is secured in place—i.e., once the mandrel1002 engages the threads of the box to be refaced—the drive shaft 1038may rotate, thereby driving rotation of the drive shaft-connectedelements 1004, 1020, 1038 at the same rate. Note that the positioningelements 1022, 1030, 1032, 1034 may also rotate because of the pins 1030extending through the primary face plate 1004. The engaging nut 1034will tend to rotate as well, as it is driven by friction in the threadeddrive shaft 1038. If the engaging nut 1034 is stopped from rotating,however, such as by an operator restraining one of the engaging nuthandles 1036, the engaging nut 1034 may advance or retreat (i.e.,travel) longitudinally along the drive shaft 1038 (see also FIG. 14 andits related description below). This lateral movement may cause thedrive shaft-connected elements 1004, 1020 to move laterally as well. Forinstance, when the engaging nut 1034 retreats proximally, the driveshaft-connected elements may advance distally in relation to the nut1034, and vice versa. In this manner, the engaging nut 1034 may causethe cutters to engage the shoulders of a tubular connection when therefacing apparatus is connected to a tubular connection.

The drive shaft 1038 may also include a drive nut 1040, to which a driveunit may be attached (see FIG. 14). The drive nut 1040 may be fixed tothe drive shaft 1038 so the drive shaft 1038 may be rotated by turningthe drive nut 1040. In some embodiments, the drive nut 1040 has multiplefaces on which a wrench or other drive system may be attachable. Thedrive shaft 1038 may also have a handle 1042 rotatable independent fromthe rest of the drive shaft 1038. The handle 1042 may allow a technicianto hold the proximal end of the apparatus 1000 while operating thehandles 1010 on the primary face plate 1004 so that when the mandrel1002 is loosened, the technician may have a stationary handhold forbearing the weight of the apparatus 1000 even while the remainder of theapparatus 1000 spins due to turning the face plates and mandrel 1002.

In some embodiments, a locking pin 1044 may be employed which can beremovably inserted through the primary face plate 1004 and into an endof the mandrel 1002 to synchronize their rotation. This is used, forexample, to engage the mandrel 1002 with the threads of the box to berefaced. Without the locking pin 1044, the primary face plate 1004 mayrotate relative to the longitudinal axis of the tool, which may make itdifficult to thread the mandrel 1002 into the box threads enough. Thus,with the locking pin 1044 in place, a wrench or other lever may beattached to the primary face plate 1004 and a torque may be applied tothe primary face plate 1004, such as by a wrench, handle, or other toolattached to a wrench aperture 1048 (see FIG. 11), the entire apparatus1000 may rotate together. This may allow the mandrel 1002 to betightened onto the tubular connection before refacing or to be loosenedafter refacing.

An air-oil chuck (not shown) may be disposed at the proximal end of thedrive shaft 1038 to provide a point of connection for a source ofcompressed air mixed with a lubricant such as an oil to supply theair-oil nozzles 1014, 1028.

Referring to FIG. 12 in particular, a side perspective view of a boxrefacer shows the refacer inserted into a box connection of a tubularmember 1200. A cutter holder 1202 is shown engaging a primary shoulderof the box connection 1200. The box refacer is not operable to refacethe tubular member 1200 in this view because the locking pin 1044 islocking the motion of the primary face plate 1004 to the mandrel 1002which is within the tubular connection around the barrel 1022.

FIG. 14 shows a side view of a box refacer engaging a box connection ofa tubular member 1200. A drive unit 1400 is attached to the drive nut1040 of the drive shaft 1038. An operator 1402 is holding a handle 1036of the engaging nut 1034 to advance or retreat the cutter holders 1012along the drive shaft 1038 in order to engage or disengage the surfaceto be refaced, as the drive shaft 1038 turns. One of the cutters 1404 isa bevel cutter in this figure, as shown by its orientation cutting abevel on the edge of the primary face of the box connection 1200.

FIG. 15 shows a partial central cross-sectional, side-oriented view of abox refacer engaging a box connection 1500 of a tubular member. The boxconnection 1500 may be refaced in this embodiment by a primary cutterheld by a cutter holder 1502, a torque-stop face cutter 1504, and abevel cutter 1058 simultaneously. The bearings for the mandrel 1002 arenot shown, but would be positioned between the barrel 1022 and themandrel 1002. The cutter holder 1502 may be fitted with a bevel cutter(see, e.g., bevel cutter 1508 in FIG. 12) or a planar face cutter.Primary face plate handles 1010, the engaging nut 1034, the drive nut1040, the locking nut 1046, and the air-oil system elements (see FIG.10) are not shown in this view. A threaded portion 1506 of the driveshaft 1038 is shown, but the face plate nut 1018 is not installed.

FIG. 16 shows an end view 1600 of a torque-stop face plate 1020 of thebox refacer of FIG. 15 installed on the drive shaft 1038 showing acutter holder 1024.

FIG. 17A shows an end view 1702 and FIG. 17B shows a side view 1700 ofprimary face plates 1004 of the box refacer of FIG. 15. The primary faceplate 1004 bears multiple cutter holders 1704, 1706 having cutters 1708.The presence of both a bevel cutter holder 1704 and a face cutter holder1706 on the face plate 1004 may enable simultaneous refacing of multiplesurfaces and/or edges of the tubular member 1500. In one embodiment,first and second sets of cutters and/or cutter holders on thetorque-stop face plate and on the primary face plate may be spaced at aprecise, fixed distance such that the distance between the refacedsurfaces remains the same as material is removed from the surfacesduring refacing.

FIG. 18 shows a side view of a drive system disassembled from a boxrefacer, such as the box refacer 1000 of FIG. 10. The drive nut 1040 maybe attached proximal to the threaded portion of the drive shaft 1038.The engaging nut 1034 may be threaded to the drive shaft 1038 and isshown without being connected to the drive nut plate 1032 (not shown).The drive nut plate 1032 could fit within the engaging nut groove 1800.Thus, it can be seen in this view that the engaging nut 1034 may moveaxially along the threaded portion of the drive shaft 1038 when turned.

A barrel 1022 may be located distally from the engaging nut 1034. Thebarrel 1022 is not covered by the mandrel 1002 or bearing 1300 in thisfigure, but is shown with the locking nut 1046 positioned at its distalend. The threaded portion 1506 of the distal end of the drive shaft isshown exposed, with the face plate nut 1018 loosened. The primary faceplate 1004 (not shown) is attachable to a primary face plate attachmentportion 1802 of the drive shaft. The torque-stop face plate 1020 (notshown) is attachable to a torque-stop face plate attachment portion1804. The torque-stop face plate attachment portion may include alongitudinal groove 1808 (see FIG. 13) for receiving the torque-stopface plate and facilitating its rotation by the drive shaft 1038.

At the proximal end of the drive shaft 1038, a stop plate 1806 may bepositioned between the drive nut 1040 and engaging nut 1034 and may keepthe engaging nut 1034 separated from a drive unit (not shown) attachedto the drive nut 1040. An attachment plate 1810 may also be integratedinto the drive shaft 1038. The attachment plate 1810 may be an integralpart of the drive shaft 1038 or welded to or threaded to the shaft 1038.The attachment plate 1038 may facilitate connection between the driveshaft 1038 and the primary face plate 1004 (not shown). For example,screws or other fasteners may be positioned to connect the attachmentplate 1810 to the primary face plate 1004, thereby affixing the primaryface plate at the primary face plate attachment portion 1802.

FIG. 19 shows a top perspective view of an air-oil attachment interface1900 that may be used to provide compressed air and oil to (or as partof) a refacing apparatus. An air supply line 1902 may provide aconnection between a source of compressed air (not shown) and an airvalve 1904. The air valve 1904 may control the flow of the compressedair to a mixing interface 1906. The mixing interface 1906 may receiveand mix air from the air supply line 1902 and an air pilot line 1908 andoil or another appropriate lubricant from an oil line 1910. The mixedair and oil may then proceed to the air chuck connector 1912 to exit theinterface 1900 and enter the refacing apparatus via an air-oil chuck(e.g., air-oil chuck 146 of FIG. 1). The mixing interface 1906 mayprovide a mixture of atomized lubricant and air supply such that thelubricant may be carried by the air flow to be sprayed onto a cuttingsurface in the refacing apparatus. The air chuck connector 1912 may beadvantageously designed as a standard air-chuck attachment interface todecrease cost of parts by using existing equipment. Advantageously, thechuck connector 1912 may be removably attachable to the air-oil chuck onthe refacing apparatus. The air-oil attachment interface 1900 may beconfigured to connect to a pin refacer or a box refacer and mayaccommodate multiple levels of air pressure and different types oflubricants based on the needs of the tubular connection being serviced,the cutters of the refacing apparatus, and conditions at the site of thetubular connection. In some embodiments, the air valve 1904 may be usedto control the pressure output of the air supply line 1902 to the mixinginterface 1906.

FIG. 20 is a flowchart showing an example embodiment method ofinstalling a refacing apparatus to a tubular connection 2000. In themethod 2000, box 2002 describes a step of cleaning the tubularconnection. The tubular connection may be cleaned, for example, bydispensing compressed air and/or oil from the air-oil system to thethreads and faces of the tubular connection, removing any existingdebris or other material that may interfere with refacing. In someembodiments, the tubular connection may be cleaned before the method2000 is practiced.

Box 2004 describes a step of inserting a locking pin into the mandrel ofthe refacing apparatus. The locking pin may be advantageously used asdescribed elsewhere in this disclosure, such as by locking the rotationof the mandrel to the rotation of a primary face plate. By inserting thelocking pin, the mandrel may rotate with the face plate even though abearing is disposed between the mandrel and the drive shaft of therefacing apparatus. In some embodiments, the locking pin may synchronizethe rotation of the engaging nut or torque-stop face plate instead (orin addition to) locking to the rotation of the primary face plate. Therotation lock may allow screwing the refacing apparatus mandrel to thethreaded box or pin portion of the tubular connection, as described inbox 2006. For example, if the mandrel is locked to the primary faceplate, handles on the primary face plate may be used to assist inscrewing the mandrel to the tubular connection. In some embodiments, awrench or wrench lever may be inserted into a portion of the refacingapparatus to provide additional leverage in tightening the mandrel intoplace. For example, a wrench may be removably insertable to the primaryface plate and extend radially from the face plate to provide additionalleverage in rotating the face plate, which, due to the locking pin,provides additional leverage in rotating the mandrel. With the mandrelin position, such as when the face plates are properly positioned toprovide refacing of the tubular connection using their cutters and themandrel is sufficiently tightly engaging the tubular connection, thelocking pin may be removed from the mandrel, as shown in box 2008.

Box 2010 describes attaching a drive unit and air-oil line to therefacing apparatus, completing the basic installation method 2000 of therefacing apparatus and preparing it for refacing of the tubularconnection. Attaching the drive unit may entail attaching a driver of adrive unit to a driving nut of the refacing apparatus.

FIG. 21 is a flowchart showing an example embodiment method of refacing2100 using a refacing apparatus installed at a tubular connection. Inthe method 2100, box 2102 describes beginning air-oil flow to thecutting surfaces. This step may require opening an air valve or othervalve that restricts flow of air and/or oil to a cutting surface. In oneembodiment, an air/oil mixture is added at approximately 120 PSI. At box2104, a step is described where the drive unit has its power turned on.In some embodiments, the drive unit may use a preset rotationalvelocity, but an adjustable-speed drive unit may also be used. Forexample, in some embodiments, the drive unit may turn the drive shaft ofthe refacing apparatus at approximately ten (10) to twenty (20)revolutions per minute (RPM), and preferably at approximately fifteen(15) RPM. These low speeds are achieved due to the design of therefacing apparatus. Providing cutting at a low speed may provide safetyeven when moving parts are accessible and may decrease a need for heavylubrication at the cutting surface. This may allow an atomized oil-aircomposition to suffice in providing lubricant and cooling to the refacedsurfaces.

Box 2106 describes the step of advancing the engaging nut in a proximaldirection to drive cutters into the tubular connection faces. In someembodiments, the drive unit may drive rotation of the entire apparatusafter installation except for the mandrel tightened to the tubularconnection. Therefore, as long as the drive unit is rotating theapparatus in the proper direction, the engaging nut may advance along athreaded portion of the drive shaft toward the tubular connection bybeing held in place while the remainder of the apparatus continues torotate. This feature may provide simplicity and ease to the operation ofthe apparatus and allows an individual operator to control the driveunit and the advancement of the engaging nut simultaneously. Forexample, the operator may hold the drive unit control with one hand andhold the engaging nut, when appropriate, with the other hand whilewatching the cutters reface the tubular connection at a relatively lowlevel of RPM, as compared with conventional refacers and grinders.

Box 2108 describes that the engaging nut and cutters are advanced untilthe faces of the tubular connection are brought within specification.The engaging nut may need to be advanced several turns to allow thecutters to completely remove warping, dents, scratches or other featuresoutside specification while refacing, but in some instances very littlematerial may be removed by the cutters and the engaging nut only needsto be advanced a low number of turns. The distance between threads onthe engaging nut may be advantageously chosen to balance providingfine-tuned adjustment of the cutters against providing speed inrefacing. This feature provides adaptability of the refacing apparatusso that each tubular connection is only refaced to the amount necessaryto comply with specifications, prolonging cutting tool life span,reducing energy and lubricant needed to reface connections, andincreasing the potential number of times that a tubular connection canbe refaced while remaining within specifications.

Box 2110 describes the optional additional step of retreating theengaging nut. By doing so, the cutters may be removed from contact withthe tubular connection faces. This may decrease the chances that thecutters or refaced surface may be damaged as the refacing apparatus isremoved. This may also allow easier inspection of the refaced surfaceand may permit the air-oil system to clear away particles and debrisfrom the refaced surfaces prior to disconnection or cutting off the flowof air to the refacing apparatus. In some embodiments, a new ordifferent cutting element may be installed for additional refacing ofthe tubular member after initially retreating the engaging nut asdescribed in box 2110 and the apparatus is removed from the tubularmember. Additional refacing may in some embodiments entail repeatingsteps 2102 through 2110 until the desired finished surface is obtained.

FIG. 22 is a flowchart showing an example embodiment method 2200 ofremoving a refacing apparatus installed at a tubular connection. In themethod 2200, box 2202 describes turning off power to the drive unit. Box2204 then describes removing the air-oil line. In some embodiments, thisstep may include closing an air supply valve and oil supply valve beforeremoving an air chuck from the refacing apparatus. Box 2206 thendescribes removing the drive unit. With the air-oil line removed, thedrive unit may be removed by sliding the drive unit proximally from thedrive nut on the refacing apparatus. Box 2208 describes replacing thelocking pin into the mandrel. This may also include replacing thelocking pin through another portion of the refacing apparatus, such asthe primary face plate, to assist in removing the mandrel from thetubular connection. With the locking pin replaced, box 2210 describesloosening the mandrel from the tubular connection and removing therefacing apparatus entirely. As with the installation step described inconnection with box 2006, a lever wrench may be employed to improveleverage for the user to complete the desired removal when the mandrelis difficult to loosen by hand or by grasping the portions of theapparatus locked to the mandrel by the locking pin.

One advantage that may be obtained by some embodiments disclosed hereinis a portable refacing apparatus. Apparatuses and methods disclosedherein may provide an apparatus operable to reface a tubular connectionwherever a source of electricity can be obtained, so they can be appliedin remote oilfield locations as needed. This may greatly reduce responsetime when tubular connections are identified as out of specification andmay reduce costs of moving large equipment or tubular connections formachining. Refacing apparatus described herein may be portable by asingle technician and transported using small vehicles, even when an aircompressor, oil reservoir, and electricity generator are brought along.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Throughout this disclosure the term “example” or“exemplary” indicates an example or instance and does not imply orrequire any preference for the noted example. Thus, the disclosure isnot to be limited to the examples and designs described herein but is tobe accorded the widest scope consistent with the principles and novelfeatures disclosed herein.

The invention claimed is:
 1. An apparatus for refacing tubularconnections, the apparatus comprising: a mandrel having a centralopening configured to receive a tubular connection; a drive systemcoupled to the mandrel, the drive system being rotatable independent ofthe mandrel, the drive system including an engagement portion, a distalfaceplate, and a proximal faceplate, the distal faceplate and theproximal faceplate each being adapted to connect to a plurality ofcutters, the mandrel being rotationally lockable relative to the distalfaceplate; an engaging nut movably connected to the engagement portionof the drive system, the engaging nut being linked to the distal andproximal faceplates and providing longitudinal movement of the pluralityof cutters upon longitudinal movement of the engaging nut along theengagement portion of the drive system.
 2. The apparatus of claim 1,wherein the engagement portion is threaded to the engaging nut.
 3. Theapparatus of claim 1, further comprising a drive unit, the drive unitoperable to provide a torque to the drive system.
 4. The apparatus ofclaim 1, wherein the plurality of cutters are configured to engage atleast two faces of a tubular connection simultaneously.
 5. The apparatusof claim 1, wherein the plurality of cutters comprises a bevel cutterand a face cutter.
 6. The apparatus of claim 1, wherein the mandrelcomprises threads, the threads configured to threadably engage a tubularconnection.
 7. The apparatus of claim 1, wherein the mandrel isrotationally lockable by a pin extending through the proximal faceplate.8. The apparatus of claim 1, wherein the proximal and distal faceplatesare linked around outer perimeters of the proximal and distalfaceplates.
 9. The apparatus of claim 1, further comprising a bearingpositioned between the mandrel and the drive system.
 10. A method ofrefacing a tubular connection, the method comprising: attaching amandrel to an end of a tubular connection, the tubular connection havingat least one face, the mandrel being connected to a cutter apparatus,the cutter apparatus having a drive system and at least one faceplateconfigured to be driven by the drive system, the drive system having adrive shaft threadably engaged to a drive nut, the at least onefaceplate having at least one cutter; rotating the at least onefaceplate relative to the tubular connection using the drive systemwithout simultaneously rotating the mandrel; advancing the at least onecutter into contact with the at least one face of the tubular connectionby rotating the drive nut relative to the drive shaft; removing materialfrom the at least one face with the at least one cutter.
 11. The methodof claim 10, wherein attaching the mandrel to the end of the tubularconnection comprises synchronously rotating the mandrel and the cutterapparatus.
 12. The method of claim 10, wherein the mandrel is attachedto the tubular connection by threadably engaging the end of the tubularconnection.
 13. The method of claim 10, wherein the at least one face ofthe tubular connection comprises a proximal face and a distal face, andthe at least one faceplate comprises at least a proximal faceplate and adistal faceplate, wherein advancing the proximal and distal faceplatesincludes advancing the proximal faceplate toward the proximal face andadvancing the distal faceplate toward the distal face.
 14. The method ofclaim 13, wherein the proximal and distal faceplates are advancedsimultaneously.
 15. An apparatus for refacing a tubular connection, theapparatus comprising: a mounting portion configured to mount to atubular connection; a drive shaft rotatable independent of the mountingportion, the drive shaft having a threaded portion; a drive nut engagingthe threaded portion of the drive shaft, the drive nut being linked to acutter configured to remove material from the tubular connection uponadvancement of the cutter toward the tubular connection, wherein thedrive nut is configured to travel along the threaded portion of thedrive shaft upon the drive nut being held rotationally stationaryrelative to the drive shaft to advance the cutter into contact with thetubular connection to remove material.
 16. The apparatus of claim 15,wherein the mounting portion mounts to an outside surface of the tubularconnection.
 17. The apparatus of claim 1, wherein at least a firstcutter and a second cutter of the plurality of cutters are mounted to atleast one faceplate of the distal and proximal faceplates, wherein thefirst and second cutters are axially spaced relative to the at least onefaceplate.
 18. The apparatus of claim 1, wherein the plurality ofcutters are adapted to simultaneously reface a surface of the tubularconnection and an edge of the surface.
 19. An apparatus for refacingtubular connections, the apparatus comprising: a mandrel having acentral opening configured to receive a tubular connection; a drivesystem coupled to the mandrel, the drive system being rotatableindependent of the mandrel, the drive system including an engagementportion, a distal faceplate, and a proximal faceplate, the distalfaceplate and the proximal faceplate each being adapted to connect to aplurality of cutters; an engaging nut threadably connected to theengagement portion of the drive system, the engaging nut being linked tothe distal and proximal faceplates and providing longitudinal movementof the plurality of cutters into contact with the tubular connection toremove material from the tubular connection upon rotational movement ofthe engaging nut relative the engagement portion of the drive system.20. A method of refacing a tubular connection, the method comprising:attaching a mandrel to an end of a tubular connection, the tubularconnection having at least one face, the mandrel being connected to acutter apparatus, the cutter apparatus having a drive system and atleast one faceplate configured to be driven by the drive system, the atleast one faceplate having at least one cutter; rotating the at leastone faceplate relative to the tubular connection using the drive systemwithout simultaneously rotating the mandrel; advancing the at least onecutter into contact with the at least one face of the tubularconnection; removing material from the at least one face with the atleast one cutter; wherein attaching the mandrel to the tubularconnection includes rotationally locking the mandrel relative to thedistal faceplate.